Wire wound armature,method and apparatus for making same



United States Patent Inventor Raymond J. Keogh Huntington, N.Y. Appl.No. 798,496 Filed Oct. 3, 1968 Division of Ser. No. 620, 306, Mar. 3,1967, abandoned. Patented 29,1970 Assignee Photocireuits CorporationGlen Cove, N.Y.

[$4] -WIRE WOUND ARMATURE, METHOD AND APPARATUS FOR MAKING SAME 6Claims, 7 Drawing Figs.

US. Cl 140/912, 29/605 Int. Cl B2lf 3/00 Field of Search 140/92.1, 92.2,93; 29/205, 605; 242/5, 7.04, 7.15, 7.16; 72/127, 133

[56] References Cited UNlTED STATES PATENTS 667,134 1/1901 Lundskog.140/922 804,250 I 1/1905 Miller 140/922 2,368,389 1/1945 Von Knauf29/605 3,346,021 10/1967 Ross... 140/922 Primary ExaminerLowe1l A.Larson Attorney-Morgan, Finnegan, Durham and Pine ABSTRACT: A wire woundmotor armature constructed by forming successive groups of single turnarmature coils, the coils within each group being in registry with oneanother, the groups being indexed relative to one another, and all coilsbeing interconnected in a wave configuration.

The apparatus for forming the winding including a rotating winding formand a wire dispensing stylus moving radially, the movements of the formand the stylus being coordinated to form the winding.

msc MOTOR DRIVE CONTROL UNI T PROGRAM INPUT mimsnumslsn 3.550.645

- SHEETEOF4 m6 INVENTOR.

1% 0 RAYMOND 1.1mm

F I63 w w WM P05 I T/ON SENSING 5TYL us MWOR DRIVE 5 o/sc MOTOR 97/DRIVE con/mm.

umr

PROGRAM INVENTUR.

INPUT RAYMOND J KEOGH A T TORNE Y5 cal fashion.

PW IRE WOUND ARMATURE, METHOD AND APPARATUS FOR MAKING SAME v Thisapplication is a divisional of copending application Ser.

No. 620,306 filed Mar. 3, 1967 in the name of Raymond J. Keogh, nowabandoned.

BACKGROUND OF INVENTION In the construction of electric motor armaturesit has been generally accepted that the coil span of the individualarma- ;ing results. By having the coil span slightly different from thedistance between magnetic pole centers there is a slight indexing of thewinding with each successive armature coil and, as a result, the coilseach have the same configuration and are uniformly distributed over thearmature surface in a symmetri- In conventional DC machines the armatureis usually formed with multiturn, preformed coils which are placed incoil slots of a laminated iron core. Since the winding must conform tothe armature slot locations, it is desirable to have a uniform indexingof the winding with respect to each successive coil such that all coilshave the same shape and allslots contain the same number of conductors.v

In recent years the low inertia, printed circuit type of motor has beendeveloped eliminating the iron and coil slots in the armature. Theprinted circuit motor usually includes a discshaped armature in whichradially extending arrays of conductors are usually bonded to oppositesides of an insulating carrier. The conductor patterns for the armatureare formed either by chemical techniques i.e. plating, or etching, or bymechanical stamping techniques. The restrictions upon the windingconfigurations in a printed circuit motor are even more severe than inthe case of a conventional motor. For example, a two-layer printedcircuit armature must be formed with single turn coils, the winding mustbe retrogressive and each coil must index the winding so that all coilshave the same configuration.

' The printed circuit motor has the advantages of high acceleration andsmooth torque, but, because of the single turn coils, can only operateat relatively low voltages.

In a copending application, Ser. No. 511,608 filed Dec. 6, I965, in thename of Robert Page Burr, having a common assigneewith this application,an insulated wire wound type of motor is illustrated as well as themethods for making the same. This armature can be formed by depositinginsulated wire around positioning pins by means of a wire dispensingstylus. Each successive coil, which can be single or multiturn, indexesthe winding slightly to obtain a uniformly progressive or retrogressivewinding distributed around the positioning pins. This type of armatureif constructed with multiturn armature coils can operate at highervoltages but is difficult to construct with automatic machinery becauseit is necessary to constantly reverse the winding direction whileforming the multiturn coils.

BRIEF DESCRIPTION OF THE INVENTION This invention relates to an improvedwinding technique for wire wound armatures which do not include slotsfor the armature coils as well as the apparatus for making the winding.

"The armature is formed by depositing insulated wire, preferably aroundpositioning pins, following a pattern forming a plurality of single turncoils which are all in registry and thus, if the pattern is continued,successive armature loops would occupy approximately the same positions.Instead ofindexing the winding with the formation of each successivearmature coil, the winding is indexed only after a predetermined numberof coils have been formed in registry with one another.

BRIEF DESCRIPTION OF THE DRAWINGS An illustrative embodiment of theinvention is set forth in the drawings which form part of thespecification and wherein;

FIG. 1 is a perspective assembly drawing of the motor; FIG. 2 is across-sectional view of the assembled motor; FIGS. 3A3D are a series ofdiagrams illustrating the armature winding sequence;

FIG. 4 is a schematic illustration of winding apparatus for forming thearmature.

ARMATURE CONSTRQCTION GENERALLY The rotating winding for disc 'machineincludes a large number of radia'lly extending insulated wire segmentsdistributed to form an annular-array which will be adjacent thestationary magnetic pole faces in the completed machine. These radiallyextending segments are interconnected to form a continuous winding whichis substantially planar, or in other words, is in the form of arelatively thin disc. Successive radially extending segments of thewinding are displaced by a distance approximately equal to the distancebetween pole centers of the associated magnetic structure and areinterconnected so that current flowing in the winding will flow in onedirection across the south poles and in the opposite direction acrossthe north poles.

The radially extending segments are preferably arranged to minimize thecrossing of conductors to thereby minimize the thickness of the armaturedisc within the magnetic airgap. The thinnest possible windingconfiguration would occur where all radially extending segments aresubstantially radial. However, when automatic winding'techniques areemployed, it is often preferable to have the radially extending segmentssomewhat skewed.

The portions of the winding which interconnect the radially extendingsegments and which lie outside the annular airgap area have a thicknessat least twice the diameter of the conductors. As the crossover areas ofthe armature winding are decreased in width, for example, to reduce thediameter of the armature, additional stacking of the conductors occursand hence the thickness of the armature winding in these areasincreases. However, the crossover connections, by definition, are notwithin the working airgap of the machine and, therefore, this increasedthickness is not detrimental to the performance of the machine.

The winding is formed in a continuous fashion utilizing insulated wireand, since the conductors are insulated, it is possible to crossconductors as desired. The copper distribution can be controlled toachieve a low copper density in the area of the airgap and a highercopper density in the thicker crossover areas outside the airgap. Thiscontrol over the relative copper density permits the designer tooptimize performance for a particular size armature disc.

An armature turn is the portion of the winding including two successiveradially extending segments. When the arma ture is constructed inaccordance with this invention the armature coils are eachsingle turncoils, and, therefore, each armature coil likewise includes twosuccessive radially extending segments. An armature loop is a portion ofthe winding which spans approximately 360? of the armature. Thus, withan eight-pole machine an armature loop includes four successive armaturecoils whereas with a l2-pole machine an armature loop includes sixsuccessive armature coils.

If the armature coils comprising a loop are in registry, the armatureloop spans exactly 360 and if successive armature loops are in registrywith the first, the successive armature loops occupy essentially thesame positions. For the purpose of this invention, armature coils aredefined as being in regis try where they are part of an armature loopwhich, if completed, would be in registry with the prior armature loopor portions thereof. Indexing of the winding occurs when successivearmature loops or portions thereof lie in positions adjacent priorarmature loops.

FIGS. 3A-3D illustrate the step by step formation of an armature windingfor an eight-pole machine including i l7 armature coils and ninecommutator segments. The winding is formed about a jig or die includinginner and outer rows of positioning pins. each such row including 27pins. The inner pins are designated 111-270 and the outer pins arelikewise designated lb-27b. The tabs for connection to the commutatorsegments are designated A-L in the order of connection. Since thearmature is for an eight-pole machine, each annature loop includes fourarmature coils. Since there are 27 positioning pins each armature coilspans approximately eight positioning pins. Since there are 117 coilsand nine commutator segments every l3th coil is connected to thecommutator.

The armature winding commences by attaching the insulated wire to one ofthe commutator connection tabs designated as tab A. Tab A is in radialalignment with the first set of positioning pins 1a and lb. The windingthen passes outside positioning pins 2a, 3b, 4b and 5b in succession.The first armature coil is then completed by passing the wire inside pin70.

Next, the second armature coil is formed by passing the wire inside pin80, outside pins lob-12b, and inside pin 14a. The winding continues bythen forming the third and fourth annature coils by passing inside pin1511, outside pins l7bl9b, inside pins Zla and 22a, outside pins24b--26b and inside pin Ia. At this point the first armature loopspanning 360 is complete is completed as is illustrated in FIG. 3A.

The second armature loop is in registry with the first armature loop andis formed following the same sequence around the positioning pins asshown in FIG. 3B. The third armature loop is also in registry as well asthe first coil of the fourth armature loop. The winding as it appearsafter formation of 3% armature loops l3 coils) is shown in FIG. 3C. Eachof the 13 coils in the first group are in registry with one another andfollow the same pattern about the positioning pins.

A commutator pull out is formed following the first group of i3 coils bypassing the winding around tab B. At this point the winding is alsoindexed so that the second group of 13 coils will lie in positionsadjacent the first group.

The winding progresses by passing outside pin 8a, outside pins 9b 1 lb,inside pins 130 and 14a, outside pins l6b-l8b, inside pins 200 and 21a,outside pins 23b25b and inside pin 27a. The winding as it then appearsafter completion of four armature loops (l6 coils), including threecoils of the second group, is shown in FIG. 3D. Coils 14-16 of thesecond group are indexed relative to coils I- l 3 of the first group.

The winding sequence for the entire 1 17 coil armature is set forth inTable I.

TABLE I Start of Outer End of 0011 plus 0011 Loop 4.

TABLE I-Continued Start of coil Outer pins End of coil Second Pullout,Second Index Point Third Pullout, Third Index Point NH I-H ouozom tetoui 1 Nut- Mi i- NHH w-cnoowwsuoowwmom-m sweetness:

Seventh Pullout, Seventh Index Point Eighth Pullout, Eighth Index PointFifth Pullout, Fifth Index Point Sixth Pullout, Sixth Index Point Loop7.

Loop 8.

Loop 9.

... 9o Uzieu zao sam z Loop 10.

Loop 11.

Loop 12.

Loop 13.

Loop 14.

Loop 15.

Loop 18.

Loop 19.

Loop 20.

Loop 21.

Loop 22.

Loop 23.

Loop 24.

Loop 25.

1 Loop 21. 22

Loop 17. I

TABLE I-Contlnued Outer End of For simplicity the number of commutatorsegments should be a submultiple of the number of armature turns. lfdead coils Start are to be avoided. the number of commutator segmentsmust coi ins c011 be odd ift the number of pole pairs is even and viceversa. Furthermore, the commutator connection points should occur f: iat regularly spaced intervals throughout the armature spaced 9 11-13 bya number of complete armature loops plus or minus one ar- ,3 i matureturn. Thus. the coil AC spacing between commutator g g Loop 0 connectionpoints can be expressed. 16 18-20 22 22 24-46 27,A Closing Coil. Y=h(p):l: 1 (4) wherein Y equals the number of armature turns betweencommutator connection points, p equals the pairs of poles 15 (alsonumber of armature turns per armature loop), n is an in- ARMATURE DESIGNCONSIDERATIONS teger multipler and the or sign is chosen to yield aprogres- In designing an armature certain factors must be known at sweor f f wmdmg asdes'red' th: outset These factors are for example: Tablell indicates the number of conductors required ln the The outsidediameter of the armature; armature for an eight-pole machine havingvanous combina- 2 The number of pole pairs in the magnetic Structure;trons or of commutator segments and distances between com- The fluxlevel which will be produced by the magnetic mutator connection pointsin accordance with the relationstructure; Sh'p: 4. The desired voltageconstant for the annature, that is, the Y= (P) 'l" 1 TABLE II first?uilzlil Jitt "uiltt %.?113El $354 No. of commutator (5 conduc- (9conduc- (13 condue- (17 conduc- (21 conduc- (25 conducsegments torpairs) tor pairs) tor pairs) tor pails tor pairs) tor pairs) voltagegenerated by the armature per 1000 r. .m., From Table ll it can be seenthat an armature having 13 com- 5. The winding resistance. mutatorsegments and commutator connection points spaced These factors areinterrelated, and, particularly factors 3, 4 by 2 /tarmature loops (9armature turns or conductor pairs) and 5 must be compatible ifareasonable armature is to result. would have a tot l of 117 rm turns; nrm ure with For the armature shown in FlGS. 3A3D these factors are ninecommutator segments and a spacing between commutaan outside armaturediameter of 3.6 inches, four pole pairs tor connection points of 3%loops (i3 conductor pairs or ar- (eight poles), a flux level of 5.3kilogauss as can be obtained mature turns) would also have a total of 1l7 armature turns; with Alnico permanent magnets, a voltage constant of2.2 and an armature with seven commutator segments and a spacvolts per1000 r.p.m., and a winding resistance of 2 ohms end ing betweencommutator connection points of 4% armature to end. loops (l7 conductorpairs or armature turns) would include a The number of armatureconductors can be determined by total of 119 armature turns. Any ofthese three combinations the following formula: could be used for thearmature under consideration wherein p N X the desired number ofarmature turns is approximately 1 16.

k, (1) A similar table could be developed for an eight-pole machine withthe spacing between commutator connection wherein it, equalsvolts/rad/sec; p equals number of pole pairs, p nts according to h f a lequals flux per pole in Maxwells, and N equals the number y=n(p) 1 (6)of conductor pairs or armature turns. 7

Substituting the aforementioned factors into Formula 1 proln thisarrangement the commutator connection points would id h f ll i occur atV4, 1%, 2%, etc., armature loops. From this additional table othercombinations can be found which could be used in k w 2 the design of anarmature having approximately 116 armature coils.

For the armature shown in FIGS. 3A--3D the combination voltlrad'lsec'(3) of nine commutator segments and commutator connection Thus, it isdetermined that approximately 97 conductor pairs p in p r ed y armatureloops armature turns) (armature turns) provides 0.022 volt/rad/sec whichin turn is has n lected which provides an armature with a total of equalto approximately 2.2 volts per 1000 rpm. 1 l7 armature turns thisselection being sufficiently close to Formula 1 assumes an armature coilshape which is caret d sir d number ofarmature turns.

j fully selected to conform to the shape of the magnets forming TheCriteria for the location of the indexing points is the the statorpoles. in the interest of simplicity and winding speed same as that forthe location of commutator connection asimplified configuration has beenadopted as shown in FIGS. p ints, and hence is represented by Formula 4.For con- 3A-3D which is approximately 80 percent efficient. Thus, tovenience, the indexing points are normally selected to coinobtain thedesired characteristics the number of annature cide with the commutatorconnection points since it is possiturns is increased by a factor of1.2, and hence, approximately ble to make both the commutator connectionand to index the ll6armature turns are required. winding as part of thesame step in the winding sequence.

However, the commutator connection points and the indexing points neednot coincide nor need the coil spacing between commutator connectionpoints be the same as that between successive indexing points.

The number of positioning pins used in forming the armature must be amultiple of both the number of commutator segments and the number ofindexing points. In the armature under consideration, the number ofcommutator segments has been selected as nine and the number of indexingpoints is also nine. Accordingly, the armature can be constructed usinga number of positioning pins which is a multiple of nine. A betterwinding distribution occurs as the number of positioning pins increases,but as the number of positioning pins increases, the complexity of thearmature winding apparatus also increases. Furthermore, a practicallimit is reached when the spacing between positioning pins of the innerrow approaches 10 pins per inch. For the winding under consideration amultiplier of three has been selected and hence there are 27 positioningpins.

The wire size is determined by measuring the approximate length of anarmature turn, multiplying this length by the number of turns in thearmature to obtain the total armature length, and by then consulting awire table to select a wire size which provides the desired armatureresistance. From a standard copper wire table number 28 guage wire isfound satisfactory for the armature under consideration, having aresistance of2 ohms end to end.

In many cases it is desirable to construct the armature usingmultistrand insulated wire as this tends to provide a thinner moreevenly distributed winding. Such an armature can be formed by dispensingmultistrand wire as the armature is formed. The same armature can alsobe made by repeating the entire windingsequence several times with asingle strand of wire. A pair of 3l gauge copper wires would provideessentially the same electrical characteristics for the winding underconsideration.

The winding technique in accordance with the invention is quite flexibleand is highly desirable since a large number of different armatures canbe made utilizing the same automatic winding apparatus and can often bemade using the same winding forms, i.e. winding forms with the samenumber of positioning pins.

MOTOR ASSEMBLY An insulated wire wound disc-type motor in accordancewith one embodiment of this invention is shown in FIGS. land 2. Themotor is enclosed within a two-part housing 1 including a base plate 2.A stationary permanent magnet structure 3, brush holders 4 and one ofthe bearings 5 are mounted on the base plate. The other bearing 6 ismounted within a central opening in the cup-shaped member 7 forming theother part of the motor housing, member 7 being secured to the baseplate at its periphery be means of screws 8.

The motor shaft 9 is journaled in bearings 5 and 6, and includes anintermediate section 10 of increased diameter. The increased diametersection is positioned between the bearings and prevents axial movementof the shaft. The motor armature 14 is mounted on shaft 9 by means of aflanged hub 11 rigidly secured to the shaft and an associated flangednut 12 which cooperates with the external threads on the shank portionof the hub. The dielectric disc 17 forming part of armature 14 isrigidly secured between the flanges of nut 12 and hub 11.

The armature winding constructed as described in relation to FIGS. 3A3Dis supported on a dielectric disc 17 shown adjacent the winding forillustration purposes. The commutator segments 16 are centrally locatedwith respect to the winding and are secured to dielectric disc 17. Theflange of hub 11 provides structural backing for the commutator toprevent distortion ofthe armature disc due to the force exerted againstthe commutator by the brushes.

The motor illustrated in FIGS. 1 and 2 is an eight-pole motor andtherefore the permanent magnet structure 3 is divided into eightsegments which provide the necessary pole faces. The permanent magnetstructure is a unitary ringshaped member provided with slots 20 whichdefine individual bosses that form an annular array of the pole faceslyingin a plane perpendicular to the axis of rotation. The magneticstructure is a cast or sintered unit fashioned from anickel-aluminum-cobalt alloy such as Alnico. The structure is magnetizedto provide pole faces of alternating magnetic polarities. A ring 18 ofsoft iron is secured to the rear of the housing by screws 19 to completethe magnetic path between adjacent pole faces. The space between ring 18and the pole face surfaces is the working airgap of the machine and mustbe sufficient to accommodate the armature and provide a workingclearance. I

A few turns of heavy, insulated wire, referred to as a charging winding,are placed around the individual pole pieces prior to final assembly.Charging winding 39 passes outside one pole piece 22, through a slot 20,and then inside the next pole piece 21, etc., twice around the unit.This winding in effect surrounds one pole piece in a clockwisedirection, and surrounds the adjacent pole piece in the counterclockwisedirection and, therefore, current flow through the charging windingtends to produce poles of alternating magnetic polarity. After flnalassembly the charging winding is energized to magnetize the permanentmagnets.

The radially extending segments of the armature winding lie within theworking airgap adjacent the pole faces. The thickness of this portion ofthe armature winding within the airgap is maintained at a minimum. Thethicker portions of the winding which include the crossover connectionsare located outside the airgap.

Brush holders 4 each include an insulated sleeve having a cylindricalbody portion 25, the end of which extends through suitable openings 27.The brushes 29 are rectangular in cross section and extend from thebrush holders through suitably dimensioned rectangular openings 28. Theend of the brush holder opposite the rectangular opening is internallythreaded and adapted to receive a flat head screw 32. When the screw isinserted, pressure is applied to the brush via a spring 30 and smallpressure plate 31, so that the brush is maintained in engagement withcommutator segments 16. The number of brushes and the placement relativeto the pole faces varies in accordance with the armature winding andcurrent carrying requirements.

WINDING APPARATUS The armature can be constructed by distributinginsulated wire upon a planar surface in continuous fashion. This isaccomplished using a winding form 40 as shown in FIG. 4 havingappropriately positioned pins 41 extending upwardly from the planarsurface so that the insulated wires forming the armature can be woundaround the pins. The pins are located in two concentric rows. Thepositioning pins in the inner row are designated 1a-27a, and thepositioning pins in the outer row are designated 1b-27b, therebycorresponding to those shown in FIGS. 3A-3D.

The insulated wire can be distributed directly upon the planar surfaceof the winding form, or upon a disc blank 44 as shown. Holes are drilledor punched into the disc blank corresponding to the positions of thepositioning pins and, hence, when the blank is dropped into position asshown in FIG. 4, the pins extend upwardly through the blank. The discblank includes the commutator segments 45 secured to the discsurrounding a central opening which will accommodate the motor shaft andhub structure. Each commutator segment includes an upwardly extendingtab, these tabs being used to position the commutator pullout loops ofthe winding.

Winding form 40 is coupled to a motor 50 which rotates the winding formin the clockwise direction. A position sensing unit 51 is coupled to themotor shaft and provides electrical signals indicating the instantaneousposition of the winding form.

The insulated wire is dispersed by a stylus 52 mechanically coupled to alead screw 53 which moves the stylus radially relative to the windingform, The movement of the stylus is controlled by a bidirectional,variable speed motor 54 coupled to the lead screw.

The operation of motors 50 and 54 is controlled from a control unit 56,respectively, via a disc motor drive 57 and a stylus motor drive 58. Thecontrol unit operates in accordance with a preselected program tocoordinate the movements of the winding form and the stylus toform thedesired winding configuration. The entire armature winding is formedwhile the winding form rotates in a single direction, and hence, sinceit is not necessary to periodically reverse the direction, relativelyhigh winding speeds are readily attainable. As the winding form rotates,position sensing unit 51 provides signals indicating the position of thewinding form, and these signals are compared with the program to controlthe corresponding radial movements of the stylus.

The winding forms and control programs are preferably interchangeable sothat the same winding apparatus can form armatures of various sizes andvarious configurations.

After the insulated wire has been distributed to form the winding it isnecessary to give it structural integrity so that the winding can bemounted on the motor shaft. There is no sigthereof:

l. The winding is formed upon the surface of a ther moplastic disc blankas shown in FIG. 4, and when completed, heat and pressure are applied topress the winding into the disc blank. The winding, particularly in -theannular airgap area, is embedded in the disc and has a thickness nogreater than the insulated wire. The same result can be achieved forforming the winding without the disc blank and thereafter pressing thethermoplastic disc down upon the preformed winding.

2. The winding can be laminated between a pair of thermoplastic discs.The winding is performed and thereafter placed between the laminateddiscs, or can be wound upon one of the disc blanks as shown in FIG. 4.Preferably, the structure is compressed in the airgap area to minimizethe thickness.

3. The winding can be formed directly upon the winding form without adisc blank and thereafter coated, as by spraying, dipping or the like,with a suitable dielectric medium to provide structural integrity.

4. The winding can be formed directly upon the winding form without adisc blank and thereafter spotted with an adhesive material to bond theinsulated wires at points where the conductors cross.

5. The winding can be formed with a heavy gauge wire which by itselfpossesses sufficient structural integrity.

SPECIFIC ARMATURE DESIGNS There are a substantial number of possiblearmature designs within the scope of the invention. Several specificexamples, in addition to that previously described, are as follows:

EXAMPLE NO. I

The positions of the commutator pullouts need not coincide with thepositions of the index points. A winding sequence for such an armaturecould be:

start at a commutator connection;

wind one full annature loop;

index ahead two pins;

wind I armature loops;

form a commutator pullout;

repeat. The parameters and predicted operating characteristics for suchan armature are as follows:

Number of Poles 8 Number of Commutator Segments 27 Number of ArmatureConductors 594 Number of Armature Turns 297 Number of Positioning Pinsper row 81 Number of Armature Turns Between Indexing Points 11 Number ofArmature Turns Between Commutator Pullouts 11 Type of WindingProgressive Wire Size #30 A.W.G. Outside Diameter of Armature "inches"3. 6 Inside Diameter of Armature do 2. 0 ArmatureResistance (includingbrushes) -ohms- 1. 9 Field Flux -kiloga.uss 5 Voltage Constant, K v./k..m.-- 5. 5 Torque Constant, K, -in.-oz. amp 7. 4 Dumping Constant, Kin.-oz./k.p.m 0. 18

EXAMPLE N0. 2

The indexing points can be separated by less than a complete armatureloop as indicated, for example, by formula 6 when n equals one. For amachine including four pole pairs the armature winding sequence wouldbe:

start at a commutator connection;

wind it of an armature loop;

index backward (retrogressive);

form a commutator pullout;

repeat.

The parameters and predicted operating characteristics for such anarmature are as follows:

Number of Poles Number of Commutator Segments 35 Number of Conductors210 Number of Turns Number of Pius in Form (Outer Row) 105 Number ofTurns Between Indexing Points 3 Number of Turns Between CommutatorSegments 3 Type of Winding Retrogressive Wire Size #24 A.W.G. OutsideDiameter of Armature iuches 6. 6 Inside Diameter of Armature do 3. 5Armature Resistance (Excluding Brushes) -ohm 0. 3 Field Flux kilogauss3. 8 Voltage Constant, K v./k.p.m. 5. 5 Torque Constant, K in.-oz./amp7. 4 Damping Constant, K in.-oz./k.p.m 1. 21

EXAMPLE No. 3

Number of Poles 8 Number of Commutator Segments Number of Conductors 150Number of Turns 75 Number of Pins in Form (outer row) 45 Number of TurnsBetween Indexing Points- 10 Number of Turns Between Commutator Segments10 Type of Winding Retrogressive Wire Size Double Strand (Bifilar) #28A.W.G. Outside Diameter of Armature inches 3 6 Inside Diameter ofArmature d 2. 0 Armature Resistance (Excluding Brushes) ohms 0. 25 FieldFlux ki1ogauss 5 Voltage Constant, K v./k.p.m 1. 4 Torque Constant, Kin.-oz./amp 1. 89 Damping Constant, K in.-oz./k.p.m 0. 176

EXAMPLE NO. 4

Number of Poles 8 Number of Commutator Segments 11 Number of Conductors154 Number of Turns 77 Number of Pins in Form (Outer Row) 44 Number ofTurns Between Indexing Points 7 Number of Turns Between CommutatorSegments T pe of Winding Progressive ire Size Double Strand (Bifilar)#28 A.W.G. Outside Diameter of Armature inches 3. 6 Inside Diameter ofArmature do 2. 0 Armature Resistance (Excluding Brushes) ohms 0. 255Field Flux -kilogauss 5. 5 Voltage Constant, K. v./k.p.m 1. 44 TorqueConstant, K in.-oz./amp 1. 94 Damping Constant, K in.-oz./k.p.m' 0. 181

EXAMPLE NO. 5

Number of Poles 8 Number of Commutator Segments 17 Number of Conductors442 Number of Turns 221 Number of Pins in Form (Outer Row) 68 Number ofTurns Between Indexing Points" 13 Number of Turns Between CommutatorSegments Type of Winding Retrogressive Wire Size Double Strand (Bifilar)#28 A.W.G. Outside Diameter of Armature inches 3. 6 Inside Diameter ofArmature do 2. 0

5 Armature Resistance (Excluding Brushes) ohms- 0. 74 Field Flux Akilogauss- 5. 5 Voltage Constant, K v./k.p.m 4. 14 Torque Constant, Kin.-oz./amp 5. 60 Damping Constant, K .in.-oz./k.p.m 0. 52

EXAMPLE-NO. 6

15 The distance between commutator connection points can be differentfrom the distance between indexing points. A winding sequence for suchan armature could be:

start at a commutator connection; wind 2% armature loops; index aheadone positioning pin;

wind one armature loop; form commutator pullout; winding 1% armatureloops (total of 4% loops) from beginning;

index ahead one positioning pin;

wind two armature loops;

form commutator pullout;

continue sequence, indexing after every 2% armature loops,

and forming a commutator pullout after every 3% armature loops.

The parameters and predicted operating characteristics for such anarmature are as follows:

Number of poles 8 5 Number of Commutator Segments 9 Number of ArmatureConductors 234 Number of Armature Turns 117 Number of Positioning PinsPer Row 27 Number of Armature Turns Between Indexing Points Number ofArmature Turns Between Commutator Connection Points 13 Type of WindingRetrogressive Wire Size 28 A.W.G. Outside Diameter of Armature inches 3.6 Inside Diameter of Armature -do- 2 Armature Resistance (includingbrushes) -ohms- 0. 5 Field Flux kilogauss 5. 3 Voltage Constant, Kv./k.p.m 2. 2 Torque Constant, K in.-oz., amp 2. 9 Damping Constant, Kin./k.p.m 1

While several specific embodiments have been described in detail itshould be obvious that there are numerous other embodiments within thescope of the invention. The invention is applicable to cylindricalarmatures as well as disc shaped armatures, and is more particularlydefined in the appended claims. 0 1 claim:

1. Apparatus for forming an armature comprising: a rotatable formincluding a plurality of circular rows of positioning pins; 1 a wiredispensing stylus for depositing wire around said positioning pins, saidstylus being adapted substantially for radial movement relative to saidform; and control means for rotating said form in a single direction andcoordinating the movement of said stylus so that insulated wire isdistributed in continuous fashion about said positioning pins by saidstylus to form successive groups of single turn armature coils, allcoils within a group being in registry and each including a pair ofradially extending winding segments displaced by a distanceapproximately in accordance with distance between adjacent pole cen- 3ters of the intended stator for the armature, the winding is indexedafter formation of each successive group so that one group of coils liesin coil positions adjacent those of a 'prior group of coils.

2. Apparatus according to claim 1 wherein said rotatable form includestwo concentric rows of positioning pins.

3. Apparatus according to claim 1 vwherein said rotatable form isadapted to receive a dielectric disc form, and said wire dispensingstylus deposits wire upon said dielectric disc form. t

4. Apparatus for forming an armature comprising:

a rotatable formincluding a plurality of concentric rows of positioningpins and a concentric row of commutator connection points;

a wire dispensing stylus for depositing insulated wire around saidpositioning pins and commutator connection points, said stylus beingadapted for radial movement relative to said form; and

control means for rotating said form in a single direction andcoordinating the movement of said stylus so that insulated wire isdistributed in continuous fashion about said positioning pins by saidstylus to form successive groups of single turn armature coils, allcoils within a group being in registry and each including a pair ofradially extending winding segments displaced by a distanceapproximately in accordance with distance between adjacent pole centersof the intended stator for the armature, the winding is indexed afterformation of each successive group so that one group of coils lies incoil positions adjacent those of a prior group of coils; and commutatorconnection loops are formed around said commutator connection points.

5. Apparatus according to claim 4 wherein said rotatable form is adaptedto receive a dielectric disc form having commutator segments securedthereto, said commutator connection points being tab's extending fromsaid commutator segments, and wherein said wire dispensing stylusdeposits said insulated wire upon said dielectric disc form.

6. Apparatus according to claim 4 wherein said control means isprogramable to provide different winding configurations.

